Ok so its gonna be years before even model 1 emulation is any good, or the stv-titan, and nobody emulated the saturn/stv-titan yet. That said MAME does seem to drive a lot of development in the arcade area.

Actually, sega Titan/STV arcade games have already been emulated. Mame runs some STV/Titan games. NebulaM2(a released model 2 emulator), runs several Model 2 games in it's early state. Satourne, a sega saturn emulator, also emulates Titan/STV games. Model 1 games have been emulated with the Model 1 emulator, Modular. Albeit most of these emus still have bugs to work out with most games, the games are running. And most of the games are very playable.